Synthetic rubberlike resinous compositions



Patented Oct. 14, 1941 SYNTHETIC RUBBERLIKE RESINOUS COM- POSITIONS JohnJ. Russell, Schenectady, N. Y., assignor to General Electric Company, acorporation of New York No Drawing. Original application April 12, 1938,

Serial No. 201,563. Divided and this application November 17, 1939,Serial No. 304,969

2 Claims.

This application is a division of my copendins application Serial No.201,563, filed April 12, 1938, and assigned to the assignee of thepresent invention.

This invention relates generally to synthetic rubber-like resinouscompositions and particularly to compositions comprising polyvinylhalide.

As is known, a polyvinyl halide, such as polyvinyl chloride, may beplasticized to yield synthetic rubber-like compositions. The most commonplasticizer for this purpose is trlcresyl phosphate. Polyvinyl halidecompositions plasticized with trlcresyl phosphate have, however, arelatively narrow temperature range in which they possess rubber-likeproperties and this materially limits their usefulness particularly atlow temperatures. For example, a composition containing 60% polyvinylchloride and 40% trlcresyl phosphate, will break on flexing attemperatures below F. Another, though less serious limitation, to itsuse as electrical insulation, is the tendency of the composition to loseplasticizer at elevated temperatures. Thus under certain acceleratedtest conditions it may lose as much as 55% of trlcresyl phosphate at 125C. over a period of 100 hours.

The ideal plasticizer for polyvinyl halide compositions is one whichwould impart properties to the plastic composition which will fit it forthe following conditions:

1. Ability to withstand mechanical abuse tendthe to damage it when usedas electrical insulation at temperatures as low as F.

2. A minimum loss of plasticizer from the composition under acceleratedtest at 125 C. for 100 hours 3. Extrudibility on wire.

By extensive investigation of the subject I have established thefollowing conclusions:

ll Cold temperature flexibility requires the plasticizer to have an Arelatively low molecular weight; 1). Along aliphatic chain; 0. Fewaromatic substituents as possible; d. Relatively little branching of thesidechain in the aliphatic substituents. 2. Loss of plasticizer atelevated temperatures is small when the compound is a. Of high molecularweight; 7). Contains many aromatic groups: c.v Has considerablebranching of the sidechains in the aliphatic groups: o3. is compact inits structure, Thus, it apparent that the problem of finding in onecompound all of the properties for the ideal plasticizer is complex.Investigation has, however, led to the discovery of a certain class ofcompounds which closely approach the ideal plasticizer. I havediscovered that esters formed by th esterification of a relatively longchain saturated aliphatic dibasic acid containing at least six carbonatoms in the molecule (that is acids of the general class (CnHZn-204)where n is at least 6 and preferably 6 to 12 inclusive) andtetrahydroiurfuryl alcohol closely approach the total of the combinationof properties desired in a plasticizer to impart low temperatureflexibility, high tensile strength and low loss of plasticizer in theplastic composition.

An example of such plasticizer is ditetrahydrofuriuryl sebacate which isa compound possessing some of each of the requirements for the idealplasticizer. It may be used in any desired proportion to obtain thedesired plasticizing effect, for example polyvinyl halide and 40%plasticizer.

Typical aliphatic dibasic acids of the class (013211404) having 6 ormore carbon atoms from which the esters may be prepared for the purposesof this invention are: adipic, pimelic, suberic, azelaic, sebaclc,nonanedicarboxylic, decamethylene-dicarboxylic, etc. The esters may beprepared by esterifyingthe alcohol and acid in any well known manner.

My invention includes not only the use of the simple esters but also theuse with polyvinyl halide of the mixed esters and mixtures of the simpleesters of the class described and in addition mixtures of these withother plasticizers for polyvinyl halides, such as, for example, inaddition to tricresyl phosphate, acetylated esters of ricinoleic acid,acetylated esters of polymerized ricinoleic acid and others includingsuch plasticizers as are mentioned in Semon Patent No. 1,929,453 of Oct.10, 1933. Obviously, the properties of the plastic compositions willvary with the proportions of the various plasticizers used and in eachcase the proportions chosen must be suited to the properties desired inthe product and the conditions of use.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. Polyvinyl halide plasticized with a tetrahydrofurfuryl ester of analiphatic dibasic acid of the class CnHZn-204, where n is at least 6.

2. Polyvinyl chloride plasticized with ditetrahydrofurfuryl sebacate,

JOEE? J. RUSSELL.

